Newsletter No 49


7 November 2007

Dear Customers & friends


The year is nearly over and looking back there is quite a lot I have achieved.

More of that (maybe) in the next and last Newsletter this year.


We are well booked right now, but still I will close shop from the 21 December until 7 January 2008.

Past experience shows that final booking has to be done at least 2 weeks before the time, unless it is something minor.

What I will do in my time off, I am not sure yet.


The most common fault I find on most vehicles is incorrectly fitted spark plugs.

Firstly you must have an R-rated plug on a Fuel injected motor to curb interference to your ECU.

No use in fitting a projected nose plug into a recessed-plug motor. Even if your piston does not punch into it, it could be that the combustion flame blows out said plug. The list carries on.

We quite commonly find Colt v6 24 valve bakkies with the incorrect plugs fitted.

The correct ones need replacing every 80 000 km’s due to the labour intensive process at getting at them (a Carrera 4 turbo is worse.)


The next common malady is a failing fuel pump.

You will realise a constant decrease in power accompanied by a miss or hesitation at certain RPM/throttle ranges.


I am mentioning this because a lot of people think that a Unichip will fix these problems.

A Unichip sets a car up right but is no magic potion.

Similar to those people bringing me something to have an aftermarket ECU fitted, without knowing what they got.

I am no magician who knows every engine made.


Case in point; a Sentra was towed in purportedly with a South African GA16DNE from a Sti fitted.

This motor did not resemble those of the Sti I know, as it had some kind of variable valve timing switch fitted.

Problem was the car would not idle and I could not make power at low RPM.

The customer gave me various versions of what was supposed to be, until I figured that I just start from scratch and charge accordingly. Finally we got the Gotech working and making some power, but even though I advised the client to get me those Cam spec’s he now wants to have it gasflowed etc.

I can only rig up the electronic controls on high-tech non SA motors if you tell me what needs to be controlled in which way.


More and more companies are offering “chip tuning”. I have put this into parenthesis because tuning means no more that setting your Engine up correctly, so that everything is working together properly. There is no way that you can tune a car without a Dyno.

Yes you can take a downtuned motor and find the correct map, thereby increasing its performance.

You can also assume that all vehicles falling under the same model are the same and can therefore tune 1 and apply the same values (called a map) to all the others. I tune at least 2 Hilux 2.7’s a week and all run different maps. Of course I can now take 100 maps and “build” a universal one with the average safe values, to be applied to all other similar vehicles to be done in future. I’ll probably gain some power and fuel economy, but not close to that of a properly tuned vehicle.


A lot of these “chips” get applied to Diesels.

A diesel will make more power if you inject more diesel.

It will not necessarily make more power by just giving it more boost- rather give it more cold air.

When I put a Diesel on the Dyno I add diesel until my AFR goes below a certain point or my EGT goes too high.

Same with timing and knock. Do you think the majority of “chip suppliers” test their product in our conditions ?


I am prepared to bet you that all things being equal I will always make more power, safely with a better fuel economy than any aftermarket “chip” !


Finally some Exhaust knowledge:

Stainless steel retains heat far more readily than Mild steel, therefore necessitating a different way in constructing a system.

Mild steel gives you more flexibility in the design approach, therefore often making more Power than stainless.


Until next time I leave you with the words of my (probably) favourite poet


Siehe Wilhelm Busch!

Halt dein Roesslein fest im Zuegel

kommst ja trotzdem nicht allzuweit

hinter jedem neuen Huegel

dehnt sich die Unendlichkeit


Nenne niemand dumm und saeumig

der das Naechste recht erkennt

denn die Welt ist so geraeumig

und der Kopf ist so beschraenkt.